1. Field of the Invention
The present invention relates generally to telecommunications systems and methods for providing a calling party name to a called subscriber having a digital phone, and specifically to handling the calling party name delivery and displaying a message indicating that a name search is being performed to a digital phone subscriber when the name is not available at the time of call setup.
2. Background and Objects of the Present Invention
In modern telecommunications networks, signaling constitutes the distinct control infrastructure that enables provision of all other services. The system which provides this signaling is known as Signaling System #7 (SS7). It can be defined as the system that enables stored program control exchanges, network databases, and other "intelligent" nodes of the network to exchange: (a) messages related to call setup, supervision, and tear-down; (b) information needed for distributed applications processing (inter-process query/response); and (c) network management information.
In addition, the Intelligent Network (IN) and the new Advanced Intelligent Network (AIN) have made possible the transfer of all types of information through the telephone network without special circuits or long installation cycles. The IN consists of a series of intelligent nodes, each capable of processing at various levels, and each capable of communicating with one another over data links. The basic infrastructure needed is composed of various signaling points, which perform both message discrimination (read the address and determine if the message is for that node), and route messages to other signaling points. The basic three types of signaling points are: (1) Service Switching Points (SSPs); (2) Signaling Transfer Points (STPs); and (3) Service Control Points (SCPs), each of which are described in more detail hereinafter.
With reference now to FIG. 1 of the drawings, the many Service Switching Points (SSPs) 100 serve as the local exchanges in a telephone network 90, a portion of which is shown in FIG. 1. The SSPs 100 also provide an Integrated Services Digital Network (ISDN) interface for the Signaling Transfer Points (STPs) 110, as is understood in the art. The ISDN protocol was first offered in the 1980's to subscribers as an intelligent interface, compatible with the IN, which offers the same services and intelligence as the IN.
The STP 110 serves as a router, and switches messages received from a particular SSP 100 through the network 90 to their appropriate destinations (another SSP 100). As is also understood in the art, the STP 110 receives messages in packet form from the SSPs 100. These packets are either related to call connections or database queries. If the packet is a request to connect a call, the message must be forwarded to a destination end office (another SSP 100), where the call will be terminated.
If, however, the message is a database query seeking additional information, the destination will be a database. Database access is provided through the Service Control Point (SCP) 120, which does not store the information, but acts as an interface to a computer that houses the requested information.
Another type of network, which can be implemented with the SS7 network, is the cellular network. Cellular telecommunications is one of the fastest growing and most demanding telecommunications applications ever. Today it represents a large and continuously increasing percentage of all new telephone subscriptions around the world. A standardization group, European Telecommunications Standards Institute (ETSI), was established in 1982 to formulate the specifications for the Global System for Mobile Communication (GSM) digital mobile cellular radio systems.
As shown in FIG. 2 of the drawings, the GSM cellular network comprises two different segments: the radio segment and the switching segment. The radio segment consists of a Mobile Station 205, e.g., the cellular telephone or transceiver itself, which is used by mobile subscribers to communicate with the cellular network 215, other mobile subscribers, and users outside the subscribed network, both wireline and wireless, and an antenna system, e.g., a Base Station System (BSS). The BSS consists of at least one Base Transceiver Station (BTS) 210, which is the physical equipment, e.g., a radio tower, that provides radio coverage to the geographical part of a cell 200 for which it is responsible. The BSS also includes a Base Station Controller (BSC) 220 connected to the BTSs 210 to serve as an interface between the radio segment and the switching segment.
The switching segment consists of a Mobile Services Switching Center (MSC) 230, which is in communication with the Base Station Controllers (BSCs) 220 via an A-bis interface 225, which is a 64-kbps digital link. The MSC 230 transmits data and other signaling information from the BSS 210/220 to the Public Switched Telephone Network (PSTN) 270 (wireline network) and to other entities within the cellular network 215.
One such entity is the Home Location Register 250, which is a database within the cellular network 215 used to store the subscriber information for all subscribers within the home service area of the service provider, e.g., user profiles, current location information, International Mobile Subscriber Identity (IMSI) numbers, and other administrative information. The HLR 250 may be co-located with a given MSC 230, integrated with the MSC 230, or alternatively can service multiple MSCs 230, the latter of which is illustrated in FIG. 2.
The VLR 240 is a database containing information about all of the Mobile Stations 205 currently located within the MSC/VLR area 230/240. If a MS 205 roams into a new MSC/VLR area 230/240, the VLR 240 connected to that MSC 230 will request data about that Mobile Station 205 from the HLR database 250 (simultaneously informing the HLR 250 about the current location of the MS 205). Accordingly, if the user of the MS 205 then wants to make a call, the local VLR 240 will have the requisite identification information without having to reinterrogate the HLR 250. In the aforedescribed manner, the VLR and HLR databases 240 and 250, respectively, contain various subscriber information associated with a given MS 205.
In order to send and receive calls between a mobile subscriber and a wireline subscriber, the cellular network 215 must be connected to the Public Switched Telephone Network (PSTN) 270. The signaling information used to request service and connect calls to and from the PSTN 270 is sent through the SS7 network. The MSC 230 connects to the SS7 network via a Signaling Transfer Point (STP) 260, which also allows digital cellular network providers to access various databases within the IN.
One feature that many digital service operators provide is caller identification. For digital phone subscribers, whether wireline, e.g., ISDN, or wireless, the calling party name and number information is typically sent to the subscriber with the first ring. However, in some cases, the name information is not available at the time of call setup. Thus, a query, e.g., to the SCP 120, must be performed to search for the name. Unfortunately, this query process can potentially take up to six seconds.
Existing technology has only provided two possible solutions for this situation where the name is not available at the time of setting up a call: (a) setup the call without the name, and display "out-of-area"; or (b) wait for the name query response, if it becomes available, and then setup the call with the calling party name. If the calling party name does not become available, even after a name query, the call can then be setup by displaying "out of area".
The Bellcore recommendation, Generic Requirement for ISDN Calling Name Identification Services, GR-1367-CORE, Issue 1, Jul. 1994, addresses the protocol of Calling Party Name Delivery over Primary Rate Interface (PRI) for ISDN. PRI is a class of ISDN service designed for larger businesses with a larger call volume that provides twenty-three 64-kbps bearer channels and one 64-kbps signaling channel. The protocol discusses the delivery of the calling party name to the subscriber, but it does not address the problem of handling call setup when the name is not initially available.
Therefore, a protocol is needed for the delivery of the calling party name when the name is not available at call setup. This includes defining the message, the information element (IE) within the message, and the structure of the IE. For example, the Bellcore recommendation for ISDN subscribers includes the Calling Party Name in a Facility Information Element (IE) in either a SETUP message, or in a separate message, such as a FACILITY message, following the SETUP message. However, the Bellcore recommendation does not address the structure of the Facility IE. Thus, the structure of the Facility IE must be defined in order to deliver the calling party name in either the SETUP message or the FACILITY message.
It is therefore an object of the invention to inform the called subscriber of a digital phone that a name query is being performed when the calling party name is not available at call setup.
It is a further object of the invention to include either the Calling Party Name, a "not available" message, a "private" message, or a "searching name" message in an initial message from the called party's end office to the called party.
It is still a further object of the invention to define the structure of a Facility Information Element for ISDN subscribers in, for example, either a SETUP message or a FACILITY message, to send the calling party name information as well as the status of the name query to the called subscriber.